In one aspect, this invention relates to peptides and proteins which inhibit RNA viruses. In another aspect, this invention relates to the use of such peptides and proteins to inhibit RNA viruses in humans.
Bishop et al (1) discovered rotavirus, a double stranded RNA virus, as a human pathogen in 1973. The virus causes diarrheal disease, especially in children and until today, there is no specific treatment. Rotavirus is implicated in infant diarrhea and the disease has great impact in developing countries. The burden of rotavirus diarrhea in the United States for ages 1 to 4 is estimated to include over one million cases of severe diarrhea and up to 150 deaths per year. (Ho et al (2)). In vitro suppression of rotavirus using a purified fraction of bovine lecithin has been reported. Smee et al (3) reported the inhibition of rotavirus by selected antiviral substances. Passive protection of neonates against rotavirus associated gastrointestinal symptoms in a nursery was observed following the oral administration of human gamma globulin containing rotavirus antibodies (Barnes et al (4)) Currently, there is no vaccine for preventive measure.
The paramyxoviruses are single stranded RNA viruses include the most important agents of respiratory infections of infants and children. Those are respiratory syncytial virus (RSV) and parainfluenza virus (PIV). RSV has been recognized as a leading cause of serious lower respiratory tract infections in infants and children under age 2 years (Parrott et al (5) and lower respiratory tract infections in adults (Dowell et al (6)). No vaccine is currently available to prevent RSV infections and the utilization of ribavirin, the only approved drug to treat RSV infections, is controversial. (Committee on Infectious Diseases (7)).
Parainfluenza viruses are ubiquitous and cause common respiratory illnesses in persons of all ages referred to as “common cold syndrome.” Wilson et al. (8) studied the use of amantadine and ribavirin as aerosol treatment for influenza A and B virus infections in mice. Gilbert et al (9) further studied the short duration of ribavirin aerosol for the treatment of influenza virus in mice and RSV infections in cotton rats. None of these drugs became commercially available for humans.
The causative agent of Acquired Immunodeficiency Syndrome (AIDS) has been identified as Human Immunodeficiency Virus, HIV. (Gallo et al (10)). The search for new and effective agents for the treatment of HIV infection continues. The following four approved antiviral drugs for the treatment of AIDS, AZT, DDI, DDC and D4T, work by blocking the viral enzyme, reverse transcriptase (Connolly et al (11)). The replication of HIV also requires another enzyme, the HIV protease (PR). A variety of successful PR inhibitors have been discovered which inhibit the replication of HIV in cell cultures (Drake et al (12)). A number of structurally diverse derivatives have been reported to inhibit the replication and cytopathic effects of the HIV in cell cultures. These include linear peptides (Frechet et al (13)), cyclic metabolites (Nakashima et al (14)) and peptide mimetic enzyme inhibitors (Gustafson et al (15)). Some of them are in use for treatment of AIDS with border-line efficacy.
Snake venom is a complex mixture of numerous bioreactive components, such as toxins, enzymes, hormones, activators, inhibitors and growth factors with a wide spectrum of biological activities. The anticoagulant, Ancrode, is the only venom-derived protein in use for human therapeutics. However, snake venoms or purified proteins from venoms were used for inhibition of polio and semiliki viruses in cell cultures and animals. It was also observed (Anderson et al (16)) that 100 μg/ml of purified phospholipase A2 (PLA2) from Pseudechis porphyriacus venom, rapidly decreased the infectivity titer of Murray valley encephalitis virus. It was also reported (Wahlstrom (17)) that PLA2 from Naja nigricolis venom partially disrupted the envelop of influenza virus. It is clear from the literature that snake venom proteins were tested for their antiviral properties two decades ago.
However, a therapeutic material to treat RNA virus infections in humans remains very desirable.
(1) Bishop, R. F., Davidson, G. P., Holmes, I. H., Ruck, B. J. Virus particles in the epithelial cells of duodenal mucosa from children with acute non-bacterial gastroenteritis. Lancet 2, 1281-1283 (1973).
(2) Ho, M. S., Glass, R. I., Pinsky, R. F., Anderson, L. L. Rotavirus as a cause of diarrheal morbidity and mortality in the United States. J. Infect. Dis. 158, 1112-1116 (1988).
(3) Smee, D. F., Sidwell, R. W., Clark, S. M., Barnett, B. B., Spendlove, R. S. Inhibition of rotaviruses by selected antiviral substances: mechanism of viral inhibition and in vivo activity. Antimicrob. Agents Chemother 21, 66-73 (1982).
(4) Barnes, G. L., Doyle, L. W., Hewson, P. H., Knoches, A. M. L., McClellan, J. A., Kitchen, W. H., Bishop, R. H. 1982. A randomised trial of oral gamma globulin in low-birth weight infants infected with rotavirus. Lancet 1, 1371-1373 (1982).
(5) Parrott, R. H., Kim, H. W., Arrobio, J. O., Hodes, D. S., Murphy, B. R., Brand, C. D., Camargo, E. Chanock, C. M. 1973. Epidemiology of respiratory syncytial virus infection in Washington, DC. Am. J. Epidemiol. 98, 289-300 (1973).
(6) Dowell, S. F., Anderson, L. J., Gary, H. E. Jr., Erdman, D. D.,Plouffe, J. F., File, T. M. Jr., Marston, B. J., Breiman, R. F. Respiratory syncytial virus is an important cause of community-acquired lower respiratory infection among hospitalized adults. J. Infect. Dis. 174, 456-462 (1996).
(7) Committee on Infectious Diseases, Use of ribavirin in the treatment of respiratory syncytial virus in infection. Pediatrics 92, 501-504 (1993).
(8) Wilson, S. Z., Knight, V., Wyde, P. R., Drake, S., Couch, R. B., Amantadine and ribavirin aerosol treatment of influenza A and B infection in mice. Antimicrob. Agents Chemother. 17, 642-648 (1980).
(9) Gilbert, B. E., Wyde, P. R., Ambrose, M. W., Wilson, S. Z., Knight, V., Further studies with short duration ribavirin aerosol for the treatment of influenza virus infection in mice and respiratory syncytial virus in cotton rats. Antivir. Res. 17, 33-42 (1992).
(10) Gallo, R., Sarin, P. S., Gelmann, E. P., Robert-Guroff, M., Richardson, R., Kalyanaraman, V. S., Mann, D., Sidhu, G. D., Stahl, R. E., Zolla-Pazner, S., Leibowitch, J. Popovic M., Isolation of human T-cell leukemia virus in acquired immune deficiency syndrome (AIDS), Science 220, 865-867 (1983).
(11) Connolly, K. J., Hammer, S. C., Antiviral therapy: Reverse transcriptase inhibition. Antimicrobial Agents and Chemotherapy, 36, 245-254 (1992).
(12) Drake, P. L., Huff, J. R. 1994. HIV protease as an inhibitor target for the treatment of AIDS. Advances in Pharmacology, 25, 399-453 (1994).
(13) Frechet, D., Guitton, J. D., Herman, F., Faucher, G., Helynck, B. Monegier du Sorbier, Ridoux, J. P., James-Surcouf, E., Vuilhorgne, M. Solution structure of RP 71955, a new amino acid tricyclic peptide active against HIV-1 virus. Biochemistry 33: 42-50 (1994).
(14) Nakashima, H., Masuda, M., Murakami, T., Koyanagi, T., Matsumoto, A., Fujii, N., Yamamoto, N. Anti-human immunodeficiency virus activity of a novel synthetic peptide, T22 (Tyr-5, 12, Lys-7) polyphemusin II): a possible inhibitor of virus cell fusion. Antimicro. Agents Chemother. 36, 1249-1255 (1992).
(15) Gustafson, K. R., Sowder II, R. C., Henderson, L. E., Parsons, I. C., Kashman, Y., Cardellina, J. H., McMahon, J. B., Buckheit Jr., R. W., Parnell, L. K., Boyd, M. R. Circulins A and B: Novel HIVinhibitory microcyclic peptides from the tropical tree Chasalia parvifolia. J. Am. Chem. Soc. 116, 9337-9338 (1994).
(16) Anderson, S. G., Ada, G. L.. A lipid component of Murray Valley encephalitis virus. Nature (London) 188: 876-880 (1960).
(17) Wahlstrom, A. Purification and characterization of PhLA2 from the venom of Naja nigricolis. Toxicon 9, 45-56 (1971).